class_docstr: A d-dimensional Bézier segment.
  
  Parameters
  ----------
  control_points : (N, d) array
      Location of the *N* control points.
docstr: Return the dimension and location of the curve's interior extrema.
  
  The extrema are the points along the curve where one of its partial
  derivatives is zero.
  
  Returns
  -------
  dims : array of int
      Index :math:`i` of the partial derivative which is zero at each
      interior extrema.
  dzeros : array of float
      Of same size as dims. The :math:`t` such that :math:`d/dx_i B(t) =
      0`
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code: def axis_aligned_extrema(self):
      """
      Return the dimension and location of the curve's interior extrema.
  
      The extrema are the points along the curve where one of its partial
      derivatives is zero.
  
      Returns
      -------
      dims : array of int
          Index :math:`i` of the partial derivative which is zero at each
          interior extrema.
      dzeros : array of float
          Of same size as dims. The :math:`t` such that :math:`d/dx_i B(t) =
          0`
      """
      n = self.degree
      if n <= 1:
          return np.array([]), np.array([])
      Cj = self.polynomial_coefficients
      dCj = np.arange(1, n + 1)[:, None] * Cj[1:]
      dims = []
      roots = []
      for i, pi in enumerate(dCj.T):
          r = np.roots(pi[::-1])
          roots.append(r)
          dims.append(np.full_like(r, i))
      roots = np.concatenate(roots)
      dims = np.concatenate(dims)
      in_range = np.isreal(roots) & (roots >= 0) & (roots <= 1)
      return dims[in_range], np.real(roots)[in_range]
  
imports: from functools import lru_cache
  import math
  import warnings
  import numpy
  from matplotlib import _api
label_desc: Use image node_id 8 for calling the BezierSegment obj's underlying member method code with example usage: obj.axis_aligned_extrema() and returns: dims,  np, np,  np